One of the principals who founded Elkus Manfredi Architects along with Howard Elkus, he is part of the team that has built a formidable portfolio and changed the Hub’s skyline. His work includes Liberty Wharf and One Marina Park Drive in Boston’s Seaport District, along with Trilogy and 1330 Boylston, a pair of buildings that redefined a section of the Fenway by replacing gas stations and one-story properties with gleaming towers. He’s at work on rebuilding the New Balance headquarters in Brighton and recasting the Edward J. Sullivan Courthouse into offices and apartments in East Cambridge.

“The quality of our lives is directly affected by the environments which we inherit, build, rebuild and improve,” he said.

Founded in 1988, the company ranked first in the state among local architectural firms with $44.1 million in total billings for 2011, according to Boston Business Journal research.

As a boy, Manfredi worked school vacations with his father, a home builder, who teamed up with residential architects. That’s where the younger Manfredi’s desire to imagine and build was born, he said. After graduating from Notre Dame with a degree in architecture in 1979, Manfredi joined The Architects’ Collaborative, the legendary Cambridge firm founded by Walter Gropius. While there was little development going on at the time, TAC had a stellar reputation and it was where he met Elkus. The two became friends and formed their professional relationship. While at TAC, Manfredi worked on a number of large projects including 855 Boylston St. in the Back Bay. The 12-story office building opened in 1986.

Later, Manfredi was sent to San Francisco to open TAC’s West Coast headquarters where he built an office of 40 staffers. That experience turned out to be a game changer. “Starting an office in a place where I knew no one gave me the confidence and convinced me I could do this,” he said. “In many ways, what you don’t know is good because you can’t be afraid.”

In 1988, Elkus and Manfredi left TAC to form their own company. The two had no clients, no staff and no projects. But they thought the timing was right. Real estate development in Boston in the mid-1980s had been strong and the vacancy rate was in the low single digits. But as soon as they launched the firm, the economy tanked and construction stopped.

“People say a recession is a good time to start a business, but I’m not sure I would recommend it,” Manfredi said. “But it worked because we had some good relationships from past work, small projects got built, and we did interior spaces and lots of planning work with corporations and developers.”

The first major project they did was the former American Express building in Providence in 1988. The 150,000-square-foot building’s success led to other work. He also completed Tico, chef Michael Schlow’s restaurant in the Back Bay. Since then, Manfredi’s reputation routinely makes him a competitor for high-profile jobs in Greater Boston.

Joseph Fallon, founder of the Fallon Co., praised Manfredi, who chose him to design One Marina Park Drive, one of the first buildings at Fan Pier.

“I’m a big fan of David Manfredi,” Fallon said. “He creates buildings in the city that everyone can be proud of. David takes the views of the developer, the city and the neighborhood and integrates them into a design that is always award winning.”